Manufacture of acid dyestuffs of the phenonaphthosafranine series



Patented Oct. 21, 1930 r E D ;j.sr TEs'rATE rf orrIcE PAUL LAEUGE Q or BASEL, SWITZERLAND, AssIGnoR TO THE FIRM: J. R. GEIGY L. A.,

" i ,OFBASEL, SWITZERLAND I Y e v r I, I

MANUFACTURE OF ACID DYESTUFFS or THE PHENONAPHTHOSAFRANINE SERIES Drawing- Application filed septe mber 1 928, Se1'ia1 No. 304,618, and in Germany September 21, 19 27.

This invention isan; improvement in or modification of the process for the manufacture of dyestufl's'of the phenonapht'hosafranine 'seri'es-described-in U; S. patent specification' S'er. No. 166,021, filed February'ft,1927. IBy the'present "invention valuable acid dyest'ufi s of the phenonaphthosafranine series are made by introducing (by means of a sulphonating agent-further sulpho-groups into a'phenonaphthosafranine16-mono-sulphonic acid insoluble in water of theg'eneral formula:

in which Rfstands for aralkyl or' aryl, R for hydrogen, alkyl, aralkyl or'aryl.

The new dyestuffs contain the one sulphogroup in the position 16 which brings about the good fastness to alkali of the dyeings'on WOOl obtained by means of them, While the further sulpho-groups introduced are in the external benzene nucleus of the azinechromogen. Since the dyeing properties and fastness properties of the acid dyestufi's of this series are strongly influenced by the numher and the positions of thetsulpho-groups andsince hithertoonly such sulphonic acids with the sulpho-group in 16-position have been made, which contain the remainingsulpho-groups in the stock ary'l nucleus of the azinechroniogen (see U. S. patent specifications Ser. No. 166,121, filed February i. 1927, Ser. No. 248,566', fi1ed January 28, 1928, and Se).- No'; 253,217,filed F ebruary 9,1928) it could not be foreseen Whether valuable dyestuffs could be produced by the present method. There are in fact obtained acid wool-dyestuffs which approximate the products described in the aforesaid specifications in respectof the pure blue tints and fastness to al'kali'and 'lightof their d eings but superior to the said products in tli eir much better fastness to fulling, I a The safranine-16-1nonosulphonic acids serving asparent material may bemade as described in U. S. specification-Sen N 0, 166,021,

- filed February 4, 1927, from the correspond A ing-isorosinduline-6-sulphonic acids by ex H changing the 6-sulpho-group for' an' unsym metrical N -alkylated para-phenylene-diam-' ine-sulphonic acid, in which the ortho-position to the free amino-group is occupied by the sulpho-group. These safranine lfi-nronosulphonic acids are 'dye'stufisinsoluble in dilute acids or sodium carbonate solutions, solubleQi-n strong acetic acid to blue solutions and in concen-.

trated sulphuric acid to green solutions, but

have no technical value. A

The following example illustrates the invention:" V

52 parts by Weight of 6-sulpho-3-ethylbenzylisorosinduline of the formula:

(which may be made by condensation of 2- plienylnaphthylamine with ethylbenzylaniline, treatment with sodium sulphite and subsequent oxidation) ,7 are boiled in a reflux apparatus With/100, parts 4; nitroso -1- A of alcohol while stirring and 25 parts of sodium 1-1nethyl-2-ethylamino-5 aminobenzcnel-sulphonate in concentrated aqueous solution are added. After addition of 20 parts of crystallized sodium acetate the whole is boiled until a portion of the product having the formula:

dissolves in sulphuric acid to a green solution. The alcohol is then distilled off and the precipitate Washed until free from salt and rapidly dried. For the sulphonation 1 part of the powdered dyestuff is introduced gradually into 5 parts of fuming sulphuric acid of 30 per cent. strength at the ordii'uu'y temperature and the mass stirred until a sample dissoly es in sodium carbonate solution. The Whole is then poured upon ice and the precipitated free dyestufl' disulphonic acid is filtered and Washed free from sulphuric acid by means of common salt solution. The dyestuif is then dissolved by means of dilute sodium carbonate solution and precipitated from this by salting out. The sodium salt having the formula:

is a dark powder, freely soluble in water toa blue solution. It dyes wool in a feebly acid bath greenish-blue. The dyeings are excellently fast to light, alkali and fulling.

In this example, the 6-sulpho-3-ethylbenzylisorosindu'line canbe replaced by the S-sulpho-3-methylbenzylisorosinduline, the 6-sulpho-3-ethylphenylisorosinduline, the 6-sulpho-3methylphenylisorosinduline or any other isorosinduline-(S-sulphonic acid; again, the 1-methyl-2-ethylamino-5-aminobenzene- 4-sulphonic acid preferably used in form the sodic salt can be replaced by the l-methyl- Q-methyl amino-5-aminobenzene-t-sulphonic acid, the 1-ethylbenzylamino-t-aminophenyl- 3-sulphonic acid, the l-diethylaminol-amino-phenyl-3-sulphonic acid or any other unsymmetrical N-alkylated para-phenylenediamine sulphonic acid having its ortho-position to the free amino-group occupied by the sulpho-group.

What I claim is 1. A process for the manufacture of acid dyestuffs fast to alkali of the phenonaphthosafranine series, consisting in subjecting a phenonaphthosa franine 16 mono sulphonic acid of the general formula:

in which R stands for aralkyl or aryl and R for hydrogen, alkyl, aralkyl or aryl, to a treatment with a sulphonating agent.

2. A process for the manufacture of acid dyestuffs of the phenonaphthosafranine series, consisting in treating an isorosinduline6-sulph0nic acid with an unsymmetrical N-alkylated paraphenylenediamine sulphonic acid having its ortho-position to the free amino-group occupied by the sulpho-group so as to obtain a phenonaphthosafranine-l6-mono-sulphonic acid of the general formula:

a 20 5 N 19 R R 17 15 11 SOHH 14 12 R R 13 in which R stands for alkyl or aryl and R for hydrogen, alkyl or aralkyl, to a treatment with a sulphonating agent, said products being valuable acid dyestuffs which in form of their sodium'salts are freely soluble in Water and dye wool in a feebly acid bath pure-blue to greenish-blue tints.

In witness whereof I have'hereunto signed my name this 25th day of August, 1928.

PAUL LAEUGER. 

